Rocket projectile



C. F. BJORK ET AL ROCKET PROJECTILE Filed Jan. 29, 1947 Dal-nld Bjork Jahn MwM/cmd5 cZM//f Aug. 23, 1949. c. F. BJoRK ET Al.

ROCKET PROJECTILE 2 Sheets-Sheet 2 Filed Jan. 29, 1947 Earfnlcf F- EIDPK Patented Aug. 23, 1949 ROCKET PROJECTILE Carola r. Bjork, Luke, Md., and John M. Woods, Madison, Viis., assignors to the United States of America as represented by the Secretary of War Application January 29, 1947, Serial No. 724,990

VV -This invention relates to rocket ordnance and `more particularly to a spinnertype rocket.

It is known to cause spin or rotation of rocket projectiles to stabilize the flight of the rocket. Our invention provides an improved spin-stabilized rocket projectile which Yhas a plurality of peripheral nozzles intermediate its ends, and which has a streamline contour.

It is one of the objects of this invention to vprovide a streamline rocket projectilewhich is spin-stabilized by the use of a plurality of Venturi nozzles.

It is another object of this invention to provide a rocket projectile which has a minimum drop-off at the nozzle mouth and hence has a relatively small drag in iiight.

It is another object of this invention to provide a rocket projectile which has a relatively high ratio of pay load to overall weight.

It is still another object of this invention to provide a rocket projectile of rugged construction which is not easily damaged in transit.

The specific nature of our invention as well as other objects and advantages thereof will be apparent from the following description of the preferred embodiment illustrated in the accompanying drawings in which:

Fig. 1 is a longitudinal section of the rocket projectile.

Fig. 2 is a transverse section on line 2-2 of Fig. 1, in the direction of the arrows.

Fig. 3 is a transverse section on line 3-3 of Fig. 1, in the direction of the arrows.

Fig. 4 is a transverse section on line d-d of Fig. 1, in the direction of the arrow.

Fig. 5 is a transverse section of the Venturinozzle carrying ring shown in Fig. 1.

Fig. 6 is a section on line 6-6 `of Fig. 5, in the direction of the arrows.

Fig. 7 is a reduced scale side elevation of the rocket projectile.

Referring to Fig. 1, for the purposes of illustration, the head of the rocket projectile is indicated by the numeral I0. The head It! supports a rearwardly extending burster tube I I, and may be provided with a nose fuse I2 in its forward portion. A forward motor casing I3 is secured to the head It by a threaded joint I4. A combined tail and rear motor casing I5 is secured to the casing i3 by an internally and externally threaded ring member i6. The forward end of the casing I5 communicates with the rear end of the casing I3. The ring member IS is provided with thirty tapered nozzles I1. As shown in Figs. 1, 2, 5 and 6, the nozzle apertures 1 Claim. (Cl. 102--49l Il are of Venturi cross-section, the axis of each 'aperture being canted with respect to the axis of the projectile. During shipping, the projectile may be provided with a plastic moisture proof seal i8 secured to the outer face of member I6 to seal the apertures I'I, thereby preventing moisture from entering the rocket motor.

Rocket propellent material in the form 'of tubular grains IQ of double-base powder is supported within the motor casings I3 and I5 on trap Wires 2li and 2I. A cage 0f nine trap wires 2&3 supports eighteen powder grains I9 around the burster tube I I, the forward ends of the wires 2B being upset at 22 and secured in a circumferential groove IU-a of the head It by a ring 23 threaded on the rear end of head l0. The rear end portions of Wires 20 may be fastened together by a wire ring member 24 in rear motor casing I5. Each wire 20 supports two grains I9 which are disposed in casings I3 and l5, respectively. The trap wires 2l form a fifteen wire cage to support nfteen powder grains I9 disposed outside of the nine grains I9 in casing I3 and adjacent the inner surface lof motor casing I3, the wires 2| being upset at their forward ends 22 which are secured in a circumferential groove I o-b in the head It by a ring 25 which is held between head I0 and flange I3' on interior of casing I3. The rear end portions of wires ZI are secured to a wire ring member 26 directly forward of the nozzle member I6. A black powder igniter 27 in the form of a doughnut may be provided in the rear end of casing I5 at the rear end of the powder assembly. The squib 28 of the igniter 2'! may be connected by wires 29 to a plug-in jack connection 3!! for connection to a firing circuit. An induction firing mechanism may be used to eliminate the use of electrical connections.

A rocket projectile embodying our invention has been successfully tested and was shown to be spin-stabilized in actual iiight. The tested projectile (Figs 1 and 7) had a total length of 21.5 inches A-C (Fig. 7), the forward motor casing I3 and head Ill being 13 inches in length A-B (Fig. 7), and the rear motor casing and tail l5 being 8.5 inches in length B-C (Fig. 7). The Venturi-nozzle-carrying ring I6 connecting the forward casing I3 and the rear casing I5 had a longitudinal thickness of 1.2 inches B-B-I (Fig. l). The outside diameter of the forward casing I 3 was 7.2 inches E-F (Fig. 7) and the outside diameter of the rear casing I5 was 5% inches G-H (Fig. '7), so that the annular face formed by the ring I 6 between the forward casing I3 and the rear casing I5, in which the Venturi nozzle Il were disposed, had a width of about 1 inch E-G (Fig. 7). This projectile was designed to carry 6.9 pounds of high explosive to an overall weight of 50 pounds. Actual operation of this projectile showed that its successful operation, viz. spin-stabilized flight projecting ,the desired quantity of` high explosive, wasv due toits novel construction as above described. The tests demonstrated that a rocket projectile of rela'- i tively short length with a large load of high explosive can be spin-stabilized in ight.

Numerous modications `of vour invention will-` be readily apparent to those skilled in the ,art.I

We claim: In a rocket projectile, the combination of a forward portion comprising ,an explosive head and a motor casing; a rear portion comprising a ycharge carrying tail and a second motor casingf communicating with said rst motor casing, the outside diameter .ofthe .rear-,portion 'being substantially '70% of the :outside diameter .of the forward portion, the length yofthe rear portion being su-bstantially A65% of-the lengthof 'the forward portion and the 'total length of the projectile being substantially three times the outside-diameter ofthe for-ward'portion; a propellent'eharge in each'ofzsaidcasings.; :and a 'ring 'disposed'.:about the forward end of vsaid rear portion, .and within theirear end Of-said-forward portion'andv pro'- CAROLD F. BJORK. JOHN M. WOODS.

REFERENCES CITED v The following references are of record in the leuioi thi-s patent:-

UNITED STATES PATENTS Great .Britaingmnvn Jan. 12,? 1,940 

